Motor-control device.



No. 854.743. PATENTED MAY 28, 1907. A. 1mm, JR.

MOTOR CONTROL DEVICE.

APPLIOA'IION run-n mm as, 1906.

2 SHEETS-SHEET 1.

- Fig. l.

. v k "Wirn esses Inventor jilflw 0 Andrew Kidddr (1 WWW 15101854343.PATBNTED MAY'28, 1907.

A. KIDD, JR;

MOTOR CONTROL DEVICE.

APPLIUATION FILED JULY 26, 1906.

' 2 snnnmsqnsnm z.

Witnesses Inventor:

Tut wank): pnnu 00., vuxnnmrdnl, n c.

UNITED STATES PATENT OFFIOE.

ANDREW KIDD, J R., OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERALMOTOR-CONTROL DEVICE.

Specification of Letters Patent.

Patented May 28, 1907.

Application filed July 25,1906. Serial No. 327,600.

To (LI/Z whom it may concern:

Be it known that I, ANDREW Kim), Jr, a citizen ol the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Motor-Control Devices,of which the following is a specification.

This invention relates to the control of electric motor circuits and hasfor its object the provision of means whereby the motor may be broughtup to running speed and the speed varied in a reliable, safe andefficient manner.

My invention relates more particularly to that type of control in whichthe motor is brought to running speed by cutting out armature resistanceand the speed then varied by variation oi field resistance.

One of the objects of my invention is to provide in combination with astarting rheostat, having a low-voltage release, a field rheostat forregulating the motor speed, the arrangement being such that it isimpossible to vary the field resistance until running conditions areestablished. I also provide means whereby when the starting rheostatreturns to ofi position, the field rheostat will be automaticallyreturned to the full field position. I

While my invention is capable of a wide variation of uses and is in nosense limited to any particular system of distribution, I have forpurposes of illustration shown it in connection with a multi-voltagesystem or more specifically the three -wire system. My invention adaptsitself particularly well to starting motors on this system.

Another object of my invention, therefore, consists in providingimproved means for starting an electric motor on multi-voltage system.In carrying out this later object, I provide starting mechanism andfield control mechanism, the arrangement being such that the motor isfirst connected across the lowvoltage mains, brought up to full speed bycutting out all the armature resistance and cutting in all of the fieldresistance. When the point of high speed at the lower voltage isreached, the motor is automatically connccted across the high voltagemains at the same time the starting resistance is automatically cut intothe armature circuit, and then the armature resistance is cut outsimultaneously with the cutting out of the field resistance, therebystrengthening the field current at the same time that the armaturecurrent is weakened, thus maintaining substan tially a constant speedwhile the motor is changed from the lower to the higher voltage.

In the accompanying drawings, Figure 1 shows my invention applied to athree-wire system of distribution; Fig. 2 shows a detailed view of thestarting handle used on the field rheostat and Fig. 3 shows my inventionapplied to the ordinary two-wire system, the construction of the fieldrheostat being somewhat modified.

Referring first to Fig. 3 in which is shown my invention in its simplestform, represents a resistance arranged to be connected in series withthe motor armature Aby means of the starting arm 11 biased to the oil-pdsition by a spring 12, in the usual manner. A no-voltage magnet 13,which I have shown connected across the line, is arranged to hold thearm 11 in short-circuited position. 14 is a resistance arranged to beconnected in series with the motor field F by means of a controlling arm15 while resistance 16 is in series with the starting resistance 1.0,for the purpose of reducing the speed of the motor after runningconditions have been established, this resistance being also controlledby the arm 15. This arm 15 is arranged to be left in any position, and.an arm 17 pivoted concentrically with the arm 15 is springpressed bymeans of spring 18, so that it will normally assume a position againstthe stop 19. The arrangement of the arms 15 and 17 is such that when thelatter returns in response to its spring pressure, it carries the formerwith it by reason of the engagement of the pin 20 with the latter arm.The retaining magnet 21 is arranged to hold the arm 17 in such aposition as to allow the arm 15 to reach the last stud of the resistance14. This magnet is connected across the line and in shunt to the magnet13, and has its circuit completed through a pair of contacts 22 by meansof a contact strip 23 carried by but insulated from the arm 11. Thecontacts are arranged so that the circuit of the magnet 21 will beclosed. when the arm 11 reaches shortcircuit position. The mode ofoperation of this form of my invention is as follows The operator startsthe motor by moving the controlling arm 1 1 to cut out the resistance 10 until it reaches the short-circuit position ,and is held there by themagnet 13. In this position the circuit of the magnet 21 is closed atcontacts 22. The arm 17 may now be moved to the right until it is heldin the position shown in the drawing by the magnet 21 The speed of themotor may now be varied either by cutting in field resistance toincrease the speed, or by cutting in armature resistance to decrease thespeed by shifting the arm 15. The last stud of the starting resistanceis connected to the segment 24 by means of conductor 25, for keeping thearmature resistance constant when the field is being varied, and asimilar segment 26 is connected with the field so as to keep the fieldresistance constant while the armature resistance is being varied. Bythis arrangement it will be seen that it is impossible to vary the fieldresistance until the armature resistance is all cut out since the magnet21 will not be energized so as to hold the arm 17 away from thecontrolling arm 15. Upon failure of voltage, the arm 1 1 will return tothe ell-position and the magnet 21 will be tie-energized, releasing thearm 17 which carries the arm to the full-field position.

In Fig. 1 in which I have shown a means of starting the motor on athree-wire system by use of my improved starting and field controlmechanism, 27 is a starting resistance arranged to be connected inseries with the motor armature A by means of the controlling arm 28biased to the oil-position in the usual manner, a no-voltage magnet 29being connected across the low-voltage mains 30 and 31 on the three-wirecircuit. The resistance 27 is provided with another series olcontactstuds 32 co-operating with controlling arm 33, and alsospring-pressed by the spring 34. A smaller number of studs is preferablyprovided and the arrangement is such that thefirst stud of the startingresistance 27 is connected with the last of the studs 32, so that as thearm 33 moves over the studs 32 in response to its spring tension, itwill cut out resistance instead of cutting in resistance as does the arm28 when similarly moved. The last stud 35 is connected with the firststud by means ol conductor 36 so that when the arm 33 is on the stop 35,all of the resistance is cut out; while when it moves to the nearestintermediate stud 32 all of the resistance is in circuit. I magnet 37 isarranged to hold the arm 33 on the stud 35, the circuit of this magnetbeing completed across the lowvoltage mains through the normally closedcontacts 38. The resistance 39 is arranged to be connected in the fieldcircuit F by means of the controlling arm 40 in the usual manner while aspring-pressed arm 41. is arranged to return the arm 40 to full-fieldposition when released by the retaining magnet 42. This magnet 42 isconnected across the high-vol- A retaining 44 which are closed by acontact strip 4-5 when the arm 23 is in running position. A pair ofnormally closed contacts 46 are likewise connected in the circuit ol themagnet 42, and the arm 41) is provided with a projection 47 havinginsulating lingers adapted to enter between the contacts 46 and 33 tobreak the circuits at these points. The mode of operation of this l orm01 my invention is as follows: The operator moves the controlling arm 29to cut out starting resistance 27 until it is held in short-circuitedposition by the magnet 29. In this position, the circuit of the magnet42 is closed across the highvoltage mains at contacts 44 by a contactstrip 45. The magnet 42 being energized. the operator moves the arm 41until it is retained by this magnet and then moves the controlling arm40 so as to cut resistance in series with the field to further speed upthe motor. hen the last stud 43 of the field resistance is reached, themagnet 42 is de-cnergized by the opening of the contacts 46, and magnet37 is likewise de-energized by the opening ol the contacts 33. Theresult is that as soon as the stud 43 is reached, the arm 41 is releasedcarrying the controlling arm 40 back to the starting position. Thede-energizing of the magnet 37 causes the arm 33 to move to the left andwhen it reaches the first stud 32, all of the resistance, 27 is cut intocircuit, the direction ol current being as follows: from lead 49 throughthe armature A to arm 28 thence through the resistance 27 and conductor50 to arm 33, segment 51 and conductor 52 back to the line 43, thearmature being thus connected across the high-voltage mains with all olthe resistance in circuit. Tl arm 33 continuing to move to the left,cuts out the resistance 27, the arm 28 being all the time held by magnet29. At the same time the arm 33 is moving to the left and cutting outresistance sons to increase the armature current, the arm 40 is likewisemoving to the lelt, increasing the field current thereby tending to keepthe speed substantially constant during the change from low-voltage tohigh-voltage. The speed may then be further increz'ised, il desired, bymoving the arm 41 into contact with magnet 42 which has again becomeenergized, and then varying the field resistance through the arm 40. Inorder to prevent the operator from holding the arm 40 when it is struckby the arm 41 and thus prevent its return to the starting position, Iprovide a compound operating arm which is shown in Fig. 2. In thisarrangement the handle 53 is provided with a short spring arm 54- havinga projection 55 fitted into a cavity in the arm 40. By thisengagementbetween the handle 53 and the arm 40, the latter is moved.over the contacts but when the arm 4-1 strikes the 1 arm 41) it movesthe latter away from the tage mains 30 and 43, through the contacts lshort arm 54 by the projection springing out seams of the cavity,carrying the arm 40 to the oilposition, and leaving the handleundisturbed .in the operators hands.

It will thus be seen that I have provided efi'ective means for startingmotors and varying the speed thereol, and while i. have shown a specificconstruction coupled With a )articular mode of operation, it should beunderstood that I do not limit my invention excepting so far as islimited by the scope of the claims annexed hereto.

il' hat ll: claim, as new and desire to secure by Letters Patent of theUnited States is,-

l. The combinatioi'i with an electric motor, ol means tor starting thesame on a multi-voltage system comprising armature control mechanism,field control mechanism, nieans lor retaining the former mechanism inrunning position across the low-voltage mains and means forauton'iatically returning the same to starting position when the fieldcontrol mechanismreaches a point of maximum speed.

lhe combination with an. electric motor, of means for starting the sameon a multi-voltage system comprising armature control mechanism, fieldcontrol. mechanism, means for retaining the Former mechanism in runningposition across the low-voltage mains and means for returning both meclanisms to starting position simultaneously when the field controlmechanism reaches the point of maximum speed.

3. The combination with an electric motor, ol means for starting thesame on a multi-voltage system comprising armature control mechanism,field control mechanism, means For retaining the former mechanism inrunning position across the low-voltage mains and means [or connectingthe motor to the high-voltage mains, with the armature resistance incircuit. when. the field. control mechanism reaches the point of maximumspeed, and then. simultaneously cutting out both resistances to maintainthe motor at substantially constant speed during the change of voltage.

The combination With an electric motor, of means for starting the sameon a multi-voltage system comprising armature control mechanism, field:control mechanism, means for retaining the former mechanism in runningposition across the low-voltage means and means for automaticallyreturning the same to starting position when the field control mechanismreaches a point of maximum speed and. simultaneousl connecting the motoracross the high-voltage mains.

5. The combination with an electric mo tor, of means for starting thesame on a undti-voltage circuit comprising armature resistance, acontrolling element therefor, field resistance, a controlling elementtherefor, means for retaining the armature controlling element inrunning position, and

means for automatically cutting the armature resistance in and out Whenthe field resistance is at the point of maximum speed Without moving thearmature controlling element from running position.

6. The combination With an electric motor, of means for starting thesame on a multi voltage system comprising armature control mechanism,field control mechanism, means for retaining the former mechanism in running position across the low-voltage mains and means for returning thesame first to starting position and then to running position When thefield control mechanism rcacl'res a point of maximum speed.

7. Means for controlling an electric motor circuit comprising armaturecontrol mechanism, means for retaining the same in shortcircuitposition, field control mechanism, means normally tending to return thesame to full-field position and means controlled by the armature controlmechanism for rendering the said return means inoperative.

8. Means for controlling an electric motor circuit comprising armaturecontrol mechanism biased to the starting position, field controlmechanism, means normally tending to return said latter mechanism tofull-field. position and means controlled by the armature controllingmechanism for rendering the said returning means inoperative.

9. Means for controllng an electric motor circuit comprising armaturecontrol mechanism, field control mechanism, means normally tending toreturn said latter mechanism to full-field position and a no-voltagemagnet controlled by the armature controlled mechanism for controllingthe returning means.

10. Means for controlling an electric motor circuit comprising armaturecontrol mechanism biased to the starting position, field. controlmechanism, means normally tending to return said latter mechanism tofull-field position and a no-voltage magnet controlled by the movementof the armature control mechanism from running position for renderingthe said returning mechanism inoperative.

1].. Means for controlling an electric motor circuit comprisingarn'iature control mechanism biased to the starting position, ano-voltage magnet therefor, field control mechanism, means normallytending to return said latter mechanism to lull-field position, and ano-voltage magnet controlled by the movement of the armature controlmechanism from running position for rendering the said. returningmechanism inoperative.

12. Means for controlling an electric motor circuit comprising armaturecontrol mechanism, field control mechanism, means normally tending toreturn said latter mechanism to full-field. position and electricallycontrolled. means responsive to movement of the armature controlmechanism from running position for rendering the said returning meansinoperative.

13. Means for controlling an electric motor circuit comprising armaturecontrol mechanism, field control mechanism, means normally tending toreturn said latter mechanism to full-field position and means responsiveto movement of the armature control mechanism for controlling thereturning means.

14. Means for controlling an electric motor circuit comprising armatureresistance and independent controlling elements therefor, one of whichis biased to running position and the other to starting position, meansfor retaining said elements in their respective operative positions,field control mechanism, and means controlled thereby for releasing oneof said armature controlling elements.

15. Means for controlling an electric motor circuit comprising armatureresistance and indepemlent controlling elements therefor one of whichhas two running positions and is biased to one of them, means formaintaining said element in the other running position, field controlmechanism and means controlled thereby for releasing said controllingelement to allow it to return to the opposite running position.

16. Means for controlling an electric motor circuit comprising armatureresistance having independent controlling elements, one of which isbiased to starting position, the other having two running positions andbiased to one of them, low-voltage magnet for retaining said elements inrunning position, field control mechanism, means controlled thereby forreleasing said latter controlling element to allow it to return to itsopposite running position.

17. Means for controlling an electric motor circuit comprising armatureresistance having independent controlling elements, one of which has tworunning positions with an intermediate starting position and biased toone of said running positions, a no-voltage magnet for retaining saidelements in running position, field control mechanism and meanscontrolled by the movement of said mechanism to a predetermined positionfor releasing said controlling element to allow it to pass from runningposition through starting position back to the opposite runningposition.

18. Means for controlling an electric motor circuit comprising armaturecontrolling mechanism having independent controlling arms, one of whichis biased to starting posi tion and the other having two running positions with an intermediate starting position and biased to one of them,field control mechanism, means normally tending to return said lattermechanism to full-field position, means responsive to movement of thefield control mechanism to full-field position for releasing said latterelement to allow it to pass from running position through the startingposi tion back to the opposite running position, and means responsive tomovement of the armature control mechanism to running position forrendering the returning means of the field control mechanisminoperative.

In witness whereof, I have hereunto set my hand this 20th day of July,1906.

ANDREW KIDD, JR. 1V itnesses G. C. HoLLrsTER, HELEN ORFORD.

